Machine for winding foil ribbon coils

ABSTRACT

A device for winding electrical coils and having particular use in winding a transformer coil consisting of interleaved layers of a strip of insulative material and a ribbon of conductive foil. One or two prewound foil reels are slidably mounted on a carriage for (independent) movement to a winding position adjacent the piece on which the coil is wound and to a second position spaced radially from the coil. The piece on which the coil is wound is rotatably held on a reeler assembly. A follower piece is biased into engagement with the outer face of the prewound reel and defines the take-off point for the foil. Nothing else touches the foil between the reel and the coil. One or two prewound reels of insulative tape are each biased into contact with a second follower piece, and the insulative tape is interleaved with the conductive ribbon. When a coil is wound except for about a turn and a half, the dereeler assembly is moved to its second position, a lead is secured to the foil, the foil is cut and winding of the coil is completed. A second coil or pair of coils may be wound on the same piece by shifting the dereeler assembly axially of the coils previously formed.

United States Patent p191 I-Iarelson [111 3,779,474 1 Dec. 18, 1973MACHINE FOR WINDING FOIL RIBBON COILS [75] Inventor: Robert G. Harelson,Florissant, Mo.

[73] Assignee: Emerson Electric Co., St. Louis, Mo.

22 Filed: Aug. 23, 1971 [21] Appl. No.: 174,141

Related US. Application Data [63] Continuation of Ser. No. 800,521, Feb.19, 1969,

abandoned.

[52] [1.8. CI. 242/56.l, 29/203 {-51 1 Int. Cl. B65h [58] Field ofSearch 242/56.1, 703,706, 242/673,.582, 58.1; 29/203, 605, 606, 607,25.42

[56] References Cited I UNITED STATES PATENTS 3.425.641 2/1969 Gallet etal. 242/56.1 3,058,201 10/1962 Richardson, Jr.. 242/703 X 3,474,37010/1969 Lightner 242/56.1 X

2,269,405 1/194; Boucher 242/103 Deputy 242/673 X Looser 242/582 PrimaryExaminer-Billy S. Taylor AttorneyPolster & Polster [57 ABSTRACT A devicefor winding electrical coils and having particular use in winding atransformer coil consisting of interleaved layers of a strip ofinsulative material and a ribbon of conductive foil. One or two prewoundfoil reels are slidably mounted on a carriage for (independent) movementto a winding position adjacent the piece on which the coil is wound andto a second position spaced radially from the coil. The piece on whichthe coil is wound is rotatably' held on a reeler assembly. A followerpiece is biased into engagement with the outer face of the prewound reeland defines the take-off point for the foil. Nothing else touches thefoil between the reel and the coil. One or two prewound reels ofinsulative tape are each biased into contact with a second followerpiece, and the insulative tape is interleaved with the conductiveribbon.

5 Claims, 6 Drawing Figures PATENIEDHEC 18 ms $779,474 SHEET 2 OF 3 FIG.5

swaiiii G- 6 ROBERT a. HARE 6 PMENTEDUEC 18 I973 SHEET 3 [IF 3 I 1MACHINE FOR WINDING FOIL RIBBON COILS BACKGROUND OF THE INVENTION Thisinvention relates'to a device for winding electrical coils of the typein which a thin, flat ribbon of conductive material is convolutely woundin an axially aligned coil. Because theelectrically conductive ribbon isfrequently very thin, it is often referred to as a foil ribbon, andthese machines are often referred to as foil coil winders. Generally,the foil ribbon is interleaved with an'insulative tape of slightlygreater width than the foil ribbon, although successive windings of thefoil ribbon may also be insulated by other means, such as bonding aninsulative strip to the foil before the coil is wound or coating thefoil ribbon with a resin. Although the high fill factor of foil coils,which allows the use of aluminum foil or strip rather than copper wirewithout sacrificing size or efficiency, makes their use in manyapplications highly desirable, it has heretofore been impractical toproduce foil coils having a small enough conductor width, on the orderof one inch or less, for most applications. Therefore, the use of foilcoils has heretofore been generally restricted to large transformers,such as those used in electrical power distribution systems, Thegreatest difficulty in making smaller width coils has been inmaintaining'a highly accurate-axial alignment of the convolute coil, inorder to prevent shorting of the windings and loss of efficiency. Theuse of edge guides almost invariably results in damaging the delicatefoil, and other methods of guiding the foil accurately have been equallyineffective, or prohibitively expensive, or both.

Machines known heretofore for winding foil coils are also unable to windcoils directly onto the form on which the coil is ultimately to bemounted, particularly when a part of that form extends considerablyradially beyond the coil, as does, for example, the leg of a transformercore made up of L-laminations. Instead, the coils are wound on an arborand carefully slipped onto the ultimate form, generally a'magneticallypermeable core. I v

Machines known heretofore have also been capable of winding only asingle coil at a time.

One of the objects of this invention is to provide a 'machine and methodfor winding foil coils which are axially aligned to'a high degree ofaccuracy, even with foil ribbon which is relatively narrow, on the orderof one inch or less.

Another object of this invention is to provide such a machine and methodwhich allow winding coils directly onto a magnetically permeable corestructure, even one of odd shape.

Still another object is to provide such a machine and method whichpermit winding more than one coil on a single core structuresimultaneously.

Other objects will occur to those skilled in the art in light of thefollowing description andaccompanying drawings. I

SUMMARY OF THE INVENTION In accordance with this invention, generallystated, a machine and method for winding axially aligned, convolute foilcoils are provided in whicha prewound reel of electrically conductiveribbon is moved from a first position adjacent a driven reeler assembly,for winding the coil, to a second position, axially aligned with thefirst position, radially'spacedfrom the reeler assembly.

The term reel isused herein to mean any prewound roll of strip material,whether it is supplied wound on a spool or without any supportstructure. The term foil is used herein to designate any thin conductivematerial, and the term ribbon to designate a strip of foil. The termaxially aligned designates alignment in a plane normal to the axis ofrotation of the coil being wound. Thus, the expression axially aligned,convolute foil coils is simply a (redundant) way of expressing the factthat the turns of the foil coil are wound upon themselves, so that theedges of the turns arealigned in a plane perpendicular to the axis ofthe coil, rather than being helical. Likewise, as applied to the twopositions of the prewound reel the term axially aligned indicates thatthe reel is not shifted in a direction parallel to the axis of rotationof the coil being wound, but rather moves in a plane normal to thataxis.

In the first position of the prewound reel the outer face of the reeledribbon is biased into engagement with a follower, and the point ofcontact between the follower and the prewound reel defines a take-offpoint for the ribbon from the reel. The prewound reel is movablysupported by a foil dereeler assembly movably mounted on a carriageassembly. Thedereeler assembly includes a brake, and the brake andfollower provide the complete means for tensioning the conductiveribbon. By providing a winding position for the'pre wound reel adjacentthe driven reeler assembly on which the coil is wound, preferablysufficiently close that the distance between the take-off point from thereel and the initial contact point on the coils is less than the initialdiameter of the largest prewound reel receivable on the reeler assembly,the machine and method of this invention allow a perfectly axiallyaligned coil to be wound, without the useof any auxiliary' alignmentequipment.

In the preferred embodiments, the conductive ribbon is interleaved withan insulative tape of slightly greater width than the conductive ribbon.The insulative tape is supplied to the reeler assembly from a prewoundreel which is carried by a tape dereeler assembly. The reeled tape ispreferably biased into engagement with a tape follower for controllingthe tension of the tape, and is located on an opposite side of thereeler assembly such that when-the dereeler assembly is in its firstwinding position, a line connecting the-center of rotation of theprewound reel of conductive ribbon with that of the coil being woundforms an angle of greater than ninety degrees with a line connecting thecenter of rotation of the coil being wound with that of the prewoundreel of tape.

In some of the preferred embodiments of this invention, 'the drivenreeler assembly is provided with a chuck which grasps the laminations ofa transformer core. Spacers may then be placed on the laminated core anda coil wound directly onto the core. Also in these embodiments, a pairof independently movable dereeler assemblies are slidably mounted on .acarriage assembly and two coils arewound on the core simultaneously. Thedereeler assemblies are also axially movable to wind a second pair ofcoils axially spaced from the first pair of coils.

In some of the preferred embodiments,the follower,

aroller, is fixed with respect to the reeler assembly and the prewoundreel is biased into engagement with it.. In

another embodiment, the follower, a shoe, is carried by the dereelerassembly and is continuously spring biased into contact with the outerface of the reeled ribbon.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings,

FIG. 1 is a view in front elevation of one illustrative embodiment ofcoil winding machine of this invention, for use in practicing someaspects of the method of this invention;

FIG. 2 is a top plan view of the device shown in FIG.

FIG. 3 is a sectional view taken along the line 3-3 of FIG. 1;

FIG. 4 is a view in front elevation of a second embodiment of machine ofthis invention for use in practicing further aspects of the method ofthis invention;

FIG. 5 is a top plan view of the device shown in FIG. 4; and

FIG. 6 is a fragmentary view in side elevation of another embodiment ofmachine of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings,and in particular to FIGS. 1-3, reference numeral 1 indicates oneillustrative embodiment of foil coil winding machine of this invention.The machine 1 includes a reeler assembly 10 driven by a power train 20,a foil dereeler assembly 30 mounted on a carriage assembly 40, a tapedereeler assembly 50, and a lead attachement assembly 60. The reelerassembly 10, drive train and carriage assembly 40 are all securelymounted to a base 70. The tape dereeler assembly 50 and the leadattachment assembly 60 are pivotally mounted on the base 70, and thefoil dereeler assembly is slidably mounted on the carriage assembly 40.

The reeler assembly 10 includes a bedplate 11 on which a spindle 12 isjournalled in a bearing 13 and a bearing 14. The spindle 12 ishorizontal and has a free forward end 15 on which a coil form 16 isremovably mounted, for rotation with the spindle l2. Spacers 17 provideproper axial positioning of the coil form 16. The coil form 16 isillustratively made of an insulative material such as stiffened asbestosand is illustratively square in cross-section, for winding square coils.The free end 15 of the spindle 12 is therefore square to fit the insideof the coil form 16. A removable cap 18 holds the coil form 16 in placeon the spindle 12. Legs 19 on the forward spacer 17 and cap 18 aid ininitial alignment of a coil being wound on the form, but perform noother guidance function.

The spindle 12 is rotated by a variable speed motor 21 of the driveassembly 20, through a belt 22 around a pulley 23 on the rearward end ofthe shaft 12. A brake 24 and clutch 25 on the spindle 12 provide smoothand controlled stopping and starting of the spindle 12.

The carriage assembly 40 includes a pair of support rods 41 and 42,which are rigidly held at their ends by blocks 43. The blocks 43 aresecured to the base 70 and hold the support rods 41 and 42 spaced aboveit. The support rods 41 and 42 are parallel with each other, and theaxis of each lies in a plane normal to the spindle 12, that is, each isaxially aligned as that term has been defined.

The dereeler assembly 30 includes a first sleeve 31 and a second sleeve32 slidably mounted respectively on the support rods 41 and 42. Thesleeves 31 and 32 are joined by a connecting plate 33. A verticalsupport bracket 34 on the forward sleeve 31 carries on its rearward facea heavy sleeve 35 in which is journaled a shaft 36, and carries on itsforward face a bracket 37. The forward end of the shaft 36 is journaledin the forward face of the bracket 37. The bracket 37 also forms ahousing in which is secured a magnetic clutch or brake 38 forcontrolling the resistance to rotation of the shaft 36. The magneticclutch 38 is continuously adjustable by means of a potentiometer, notshown. Suitable spacers 39 on the distal, rearward, end of the shaft 36provide exact axial alignment, as that term has been defined, of aprewound reel of conductive foil ribbon 81 with the coil winding form16. The prewound reel 80 is slipped on to the distal end of the shaft 36and held by a lock 39a. By way ofillustration, the prewound ribbon maybe bare aluminum 1 l/l6 inches wide and 0.008 inch thick.

The entire foil dereeler assembly 30 is movable to a first position,shown in solid lines in FIG. 1, adjacent the reeler assembly 10 and to asecond position, shown in broken lines in FIG. 1, spaced from the reelerassembly 10. The foil dereeler assembly 30 is biased toward its firstposition by a hanging weight 83 secured to the connecting plate 33 ofthe foil dereeler assembly 30 by a chain 85 over a sprocket 87 on thebase 70. When the foil dereeler assembly 30 is in its forward position,the outer face of the prewound reel 80 is biased into engagement, at apoint 82, with a follower in the form of a roller 91 freely rotatablysupported by a bracket 93 extending forwardly from the bedplate 11 ofthe reeler assembly 10. The axis of rotation of the roller 91 isparallel with that of the spindle 12 of the reeler assembly and theshaft 36 of the foil dereeler assembly. The axis of rotation of theroller 91 and the axis of rotation of the reel 81 lie in a plane whichis approximately horizontal, and the coil winding form 16 is positionedabove and slightly to the left, as viewed in FIG. 1, of the point ofcontact between the roller 91 and the reel 80. Therefore, when a freeend of the ribbon on the reel 80 is secured to the coil winding form 16,and the form 16 rotated in a counterclockwise direction as viewed inFIG. 1, the roller 91 displaces upward slightly the takeoff point of theribbon 81 from the reel 80. It will be seen that the ribbon contacts theroller 91 over a short are of its curved surface.

The dereeler assembly 30 may be moved manually, to the right as viewedin FIG. 1, to its second position shown in broken lines in FIG. 1, andlocked by a latch 95 to a support block 43. As will be explained morefully hereinafter, in the second position of the dereeler assembly 30,the reel 80 should be spaced from the reeler assembly 10 a distance atleast equal to the width of the lead attachment assembly 60.

By way of illustration, the largest prewound reel 80 usable on thedereeler assembly 30 may be 12 inches in diameter. The greatest lengthof ribbon 81 from the takeoff point 82 to the point of contact with thecoil being wound, as shown in FIG. 1, may be about 7 inches. The lengthof ribbon between these points will of course vary slightly as the coilform 16 turns through a quarter revolution.

The tape dereeler assembly 50 includes a pair of parallel axiallyaligned rails 51 each including a set of holes 52. An upright H-shapdyoke 53 is pivotally mounted between the rails 51 by pegs 54 thorugh onepair of holes 52 in the rails and through one pair of a set of matingholes 55- in the lower part of the legs of the H- shaped yoke 53. Ashaft 56 is held by lock pins 57 in seats 58 at the upper margins of thelegs of the H- shaped yoke 53. The shaft 56 freely rotatably supports aprewound reel 84 of insulative tape 86. A spring 92 secured to theadjacent support block 43 of the support rod 42 and to the cross braceof the yoke 53 biases the prewound 'tape reel 84 into contact with afollower in the form of a roller 97 freely rotatably mounted on aforwardly extending bracket 99. The axis of rotation of the tape roller97 lies in a common horizontal plane with that of the roller 91 and theprewound reel 80. The roller 91 and roller- 97 are arrangedsymmetrically with respect to the spindle -12 of the coil reelerassembly 10.

The holes 52 in the support rails 51 and the holes 55 in the yoke 53 arespaced apart a distance such that,- when the .yoke 53 is pivotallysecured between any of the pairs of holes 52 in the rail 51, the shaft56 and the axis of the'roller 97 lie on the same arc having its centeratthe pin 54. Thus, for each position of the yoke 53, the point ofcontact between the tape reel 84 and the roller-97, with respect to thefixed structure of the machine, remains the same as the roll of tape 84unwinds. Therefore, moving the yoke 53 from one position to a hole 52further removed from the vertical increases the resistance to rotationof the tape reel 84 essentially independently of the diameter at thatinstant of the tape reel 84. Thus, tensioning of the tape may be keptsufficiently constant by moving the yoke to holes spaced farther fromthe reeler assembly as the diameter of the tape roll 84 decreases.

. The contact point 89 between the tape reel 84 and the roller 97 likewise defines the takeoff point of the tape from the reel 84. However, itwill be seen that the tape 86 rides on the roller 97 through a muchgreater arc, on the order of 60, than does the foil 81 on the roller 91.t

When the tape86 is attachedto the coil form 16 and the form 16 rotatedcounterclockwise as viewed in FIG. 1, the distance from the takeoffpoint 89 to the point of contact with the coil is, illustratively, amaximum of about 6% inches.

Merely by way of illustration, the tape 86 may be a woven fiberglasstape 1% inch wide and 0.004 inches thick. The maximum diameter of thetape roll may be 5 inches.

Also by way of illustration, the rollers 91-and 97 may be 2% inch indiameter and their axes of rotation may be spaced about 6 inches fromeach other and from the axis of rotation of the spindle 12. The rollers91 and 97 may be made of hard rubber.

The lead attachement assembly 60 includes a spot welder 61 having anopen jaw 63 for receiving the conductive ribbon 81. The welder 61 ispivotally mounted to the base 70 on an axis parallel to the rearwardsupport rod 42 of the carriage assembly 40, and spaced rearward of it.The welder 61 is normally rotated rearward to a first stop position, asshown in FIG. 2, and when the dereeler assembly 30 is moved to itssecond position spaced from the reeler assembly 10, the welder 61 isswung forward to a second position, in which the open jaw 63 is axiallyaligned with the foil ribbon 81 for welding a lead to the ribbon 81.

I this invention, is as follows.

dereeler assembly 30 is in its second position, radially spaced from thereeler assembly 10. The diameter of the reel 80 is preferably themaximum usable, i.e., l2

inches, for efficiency of operation. The prewound tape roll 84 is placedon the shaft 56 of the tape dereeler assembly 50 and the shaft 56 issnapped into its slots 58 in the yoke 53. Each prewound reel ofconductive rib-- bon and insulative tape, of course, is used for windinga large number of coils. A reel isreplaced'only when it containsinsufficient material to wind another coil.

A coil form 16 is then slipped onto the squared end 15 of the spindle 12of the reeler assembly 10, along with the proper spacers 17 and securedby the cap 18. While the dereeler assembly 30 is still in its secondposition, the welder 61 is moved to its second position, in which itsopen jaw 63 is axially aligned with the foil ribbon 81. The loose end ofribbon on the reel 80 is manually placed in the jaw 63 for welding astart lead 96 to the ribbon 81 at a point spaced a desired distance,illustratively one inch, from the end of the ribbon, to give the desiredplacement of the lead 96 asexplained hereafter. It will be seen that thewelding operation is performed a sufficient distance away from the coilform 16 to prevent any danger of injury to it.

When the lead 96 has been welded to the ribbon 81, the lead attachmentassembly is swung back to its first position, and the latch 95 isreleased to allow the dereeler assembly 30 to move to its first positionadjacent the coil form 16, with the ribbon reel in contact with theroller 91 and a short strip of ribbon 81 extending above the point ofcontact. The loose end of the woven glass tape 86 on the roll 84 isbrought over the roller 97 and manually held to the free end of theribbon 81. The free end of the glass tape 86 preferably extends aboutone-half inch beyond the ribbon 81. The ends of the tape 86 and ribbon81 are then placed over a corner of the form 16, with the lead 96 lyingat the center of an adjacent face of the form and extending between legs19 of the cap 18. A strip of polyester pressure-sensitive tape,notshown,is thensecured in axial alignment with the coil form 16 over thelead 96, the end of the ribbon 81, the end of the tape 86, and theadjacent face of the coil form 16, for securing the tape 86 and ribbon81 to the form 16,.and for reinforcing the welded joint between theribbon 81 and thelead 96. If desired, a piece of insulation may beplaced along the attached part of the lead 96 and held by thepressuresensitive tape. The form 16 is then rotated by handcounterclockwise, as viewed in FIG. 1, to reduce the strain on thepressure-sensitive tape when the power train 20 is energized. The motor21 is then energized and the clutch 2S engaged to give a smooth start.The coil form 16 quickly reaches a predetermined rate of revolution,which is preferably on the order of 30 revolutions per minute.

It will be seen that the reels, rollers, and coil form are so placedthat the take up angles of the ribbon 81 and tape 86 onto the coil form16 are about90 degrees separated..Therefore, the tape 86 is always laidcompletely across a face of the coil and around'a trailing corner beforethe ribbon 81 is laid over it. Therefore, there is no slippage betweenthe tape 86 and the ribbon 81, and

tensioning of each component is essentially independent of the other.

It will also be seen that the tensioning of the tape 86 and ribbon 81will vary slightly as the coil is wound. This variation,'however, hasbeen found not to affect the finished coil adversely. When all but a fewof the desired number of turns have been wound on the coil, the electricmotor 21 is de-energized and the brake 24 applied to stop rotation ofthe coil form 16 smoothly and quickly. About a turn and a half shouldremain to be wound when the coil form 16 stops rotating, The dereelerassembly 30 is then moved to its second position spaced from the reelerassembly 10 and its latch 95 is secured to the adjacent support block43. The reach of ribbon 81 between the coil 98 and the reel 80iscarefully lifted, the lead attachment assembly 60 is carefully swungforward, and the ribbon 81 carefully placed in theopen jaw 63. A finishlead is then welded to the ribbon 81, the coil form 16 is turned ashortway by hand, and a second start lead is welded to the ribbon 81. Thelead attachment assembly 60 is then swung back to its first position.The ribbon 81 is then cut between the finish lead and the second startlead,

about one-eighth inch from the finish lead, and the coil' 98 iscompleted by manually turning the form 16. The glass tape 86 is cutabout one-half inch beyond the end of the ribbon 81. A strip ofpressure-sensitive polyester tape is then wrapped entirely around thecoil, securing a short strip of insulation over the finish lead ifrequired'. The cap 18 holding the coil form 16 on the spindle 12 is thenremoved and the coil form 16 is taken off the spindle 12. The coil 98may then either be set aside or immediately slipped over a magneticallypermeable core, such as a laminated L-shaped transformer core half.

If it is desired to wind coils around the first coil 98 wound on acoil'form 16, these coils may be wound before the coil form 16 isremoved from the spindle 15. Spacers may be placed at the comers of thecoil 98, and the second coil wound in the same manner. If the first coilwound on a coil form 16 is wide, it may be desired to wind second andthird coils, each half the widthof the first coil, over the first coil.A new foil reel and new tape reel, each half the'width of thecorresponding first reel, are placed on their respective dereelerassemblies with spacers holding them forward. The second coil is thenwound. After leads have been attached, the third coil is wound by movingthe dereeler spacers to shift the foil and tape reels rearward adistance equal to the width of the second coil, and then winding thethird coil in the same manner as the first two. Usually, of course, itis preferable to wind a large number of coils of the same width at thesame time and then to wind coils of a different width over them, inorder to avoid frequent handling of the prewound reels.

Successive coils are wound in precisely the same manner. It will be seenthat as the diameters of the prewound reels 80 and 84 decrease, the sameresistance to their rotation creates a greater tensioning of the ribbon81 and tape 86 respectively. The ribbon 81 is particularly sensitive tochanges in tensioning, whereas the tape 86 is remarkably insensitive tothe changes encountered in normal operation. Therefore, the. magneticclutch 38 must be adjusted to a lower (freer tuming) setting by means ofits potentiometer as the reel 81 unwinds, and the yoke 53 of the tapedereeler assembly may be shifted to holes 52 closer to the reelerassembly 10, that is from the position shown in broken lines in FIG. 1to the position shown in solid lines in FIG. 1. Although it is possibleto provide a feedback system from the drive train 20 for automaticallyadjusting the potentiometer of the magnetic clutch 38, it has been foundthat one or two manual stepwise adjustments of the potentiometer aresatisfactory.

It will also be seen that if it were desired to provide a coil wound inthe opposite direction (that is, with leads extending from the oppositeside), it is possible to reverse the direction of rotation of the coilform 16. In this case, the ribbon 81 and the tape ,86 follow paths whichare mirror images of the path followed by the other when the coil form16 is rotated counterclockwise as viewed in FIG. 1. Therefore, the tape86 will be laid over the ribbon 81, but the angle between the tape 86and ribbon 81 will again be about 90, and their tensioning will again beessentially independent of each other. Although the particular. reelerassembly 10 of this illustrative embodiment makes winding the coils inopposite directions generally unnecessary, this feature may be usefulwith other reeler assemblies, as explained hereinafter.

Referring now to FIGS. 4 and 5, reference numeral 101 indicates a secondillustrative embodiment of foil coil winding machine of this invention,for use in practicing further aspects of the method of this invention.The machine 101 includes a reeler assembly driven by a power train 120,a first dereeler assembly 130, a second dereeler assembly 230, a tapedereeler assembly 150, a lead attachment assembly 160, and a base 170.The lead attachment assembly 160 is mounted on a lead assembly carriage260, and a forward part of the reeler assembly 120, dereeler carriageassembly 140, reelerassembly carriage 210, and lead attachment carriage260 are all secured to the base 170. The rearward part of the reelerassembly 110 is secured to the drive assembly 120 for rotation with it.

The forward part of the reeler assembly 110 includes a pillow block 111slidably mounted on the reeler assembly carriage 210 for movement to arearward position (toward the rearward half of the reeler assembly 110),shown in FIG. 5, and to a forward position (away from the rearward halfof the reeler assembly 1 10). The pillow block 11 rotatably supports aforward chuck 112 the jaws 113 of which are tightenable by a clamp screw114 for grasping the forward end of a structure to be wound. Therearward face of the chuck 112 carries a forward winding plate 115having a large slot 116 for receiving a structure to be wound, and asmall slot 1 17 for receiving a lead of a coil being wound.

The rearward part of the reeler assembly 110 includes a chuck 118, whichmay be a standard two-jaw chuck, the jaws 119 of which are adapted tograsp the rearward end of the structure being wound. A rearward windingplate 121 on the chuck 118 includes a slot 122, which in use is alignedwith the slot 116 on the forward plate 115, and a small slot normal tothe slot 122 for receiving a lead of a coil being wound. The chuck 118is secured to a rotating shaft 123 of the power train 120. The axis ofrotation 124 of the shaft 123 is, of course, the axis of rotation forall of the rotating parts of the reeler assembly 110,

The drive train also includes a magnetic clutchbrake 125, for stoppingthe rotation of the shaft 123 smoothly and accurately, and for releasingthe shaft for free manual rotation when desired. It also includes avariable spe'edelectric motor 126 connected tothe shaft 123 by a pulley127 for controlling the rate of rotation of the shaft 123 to aprecontrolled, continuously variable, rate, and a'magnet wheel 128carrying around its margin a set of ten magnets l28a-which cooperatewith a magnetically triggered counter switch 129 for activating theclutch-brake 125 and thus stopping the rotation of the reeler assembly110 after a pre-set number of revolutions.

Each of the dereeler assemblies 130 and 230 includes a bedplate 131slidably mounted on the carriage assem bly 140. The bedplate 131 of theforward dereeler assembly 130 is mounted on a pair of axially alignedshafts 141 of the carriage assembly 140, and the bedplate 1310f therearward dereeler assembly 230 isslidably mounted on a pairof axiallyaligned shafts 142.

The shafts 141 and 142 are mounted to the base 170, g

and spaced from it, by a pairof support blocks 143. Each bedplate 131 isU- shaped in a cross-section taken along a plane perpendicular to thecarriage shafts 141 and 142. The upstanding arms 132 of each of the U-shaped bedplates- 131 have mounted between them a pair of horizontalsupport rods 133, the axes of which are normal to the axis of thesupportshafts 141 and 142 in plan view, as seen in FIG. 5. Slidably mounted .onthe support rods 133 on each dereeler assembly 130 and 230 is abifurcated support bracket 134, the branches 135 of which have journaledbetween them a shaft 136 and rigidly support between'them a magneticclutch 137 for controlling the resistance to rotation of the shaft 136.The axes of rotation 138 ancl 238 respectively of the shafts 136 of theassemblies 130 and 230 are parallel to the axis of rotation 124 of thereeler assembly 110. At theirfree, axially inner ends (the rearward endfor the forward assembly 130 and the forward end for the rearwardassembly 230) the shafts 136 have removably mounted on them appropriatespacers in the form of spools 139 having threaded retainer caps 139a forsecuring prewound reels 180 of foil ribbonv 181 to the inner faces ofthe spools 139. Each dereeler assemreeler assembly 110, by means of arod arm at the axially outer end of the rod 233 and a spring arm 235 atthe axially inner end of the rod 233. A spring 236'from the spring arm235 to the'shoe arm 232 biases the shoe 231 into contact with the outerface of the reel 180.

Each of the dereeler assemblies 130 and 230 is independently movablefrom a first position adjacent the reeler assembly 110 to a secondposition spaced from' it. In FIGS. 4 and 5, the forward dereelerassembly 130 is in the second position and the rearward dereelerassembly 230 is in the first position. In this embodiment, the dereelerassemblies are alternatively biased toward their first position andtoward their second position by a pneumatic control system whichincludes a pair of air cylinders 144 powered by a standard industrialsource of compressed air, not shown. The air cylinders 144 are clevistype cylinders and are controlled by a standard four-way double solenoidvalve, not shown, for electrically controlling the direction 'of'biasfrom a control panel 145. When one of the dereeler assemblies is movedto its first position adjacent the reeler assembly an arm 146 from itsbedplate 131 through a slot 172v in the base 170 to the clevis of itsair cylinder 144 contacts an adjustable stop 147 and is continuouslybiased into engagement with it until the control is reversed and thedereeler assembly moved to its second position. When it reaches itssecond position, its bedplate 131 contacts a limit switch 148 andthereby disconnects the air supply to its air cylinder 144. ln-thissecond position, the bracket 134, hence the reel 180, can be movedforward or rearward on the bedplate by pneumatically releasing a springloaded latch pin 237 mounted through the bedplate 131 and extending intoone of two holes in the bracket 134. The bracket 134 and prewound reel180 are thereby movable to an inward position or an outward position.The latch pin 237 is released by one of a second pair of pneumaticcylinders 238. Energizing the control solenoid of one of the aircylinders 238 causes it sequentially to extend and to retract a- 'magnetwhich engages and withdraws the latch pin 237. The reel 180 and itssupport structure may then be shifted .to the other'position before themagnet retracts below the level of its housing 239 and releases thelatch pin 237. The support bracket 134 may then be shifted until thelatch pin 237 snaps into place. As shown in FIG. 5, the first dereelerassembly 130 is in its outward position and the second dereeler assembly230 is in its inward position. lt will be seen that if both dereelerassemblies are moved to their inward positions, using ribbon and spoolsof the width shown, the reels would be separated only by the extremelythin keeper nuts 139a and could wind axially aligned coils having theirconductors extremelyclose to each other. It will also be seen that coilsof slightly greater than twice the width of the coils shown in FIG. 5could be wound simply by moving the support structure of the seconddereeler assembly 230 to its outward position. Of course, by changingthe axial dimension of the spools 139, either two or four coils of quitevarying width can be wound.

. The tape dereeler assembly 150 includes a pair of rotatable shafts 151snapped into a pair of support structures 152 and 252 secured to thebase 170. The support structure 152' 'is positioned forward of thesupport structure 252 and radially nearer the reeler assembly 110. It isalso somewhat shorter than the support structure 252. Tape reels 184 ofinsulative tape 186 are positioned on the shafts 151 by spacers 156. Theaxial positions of the reels 184 can be changed by substituting newspacers 156 and by switching them to the opposite sides of the tapereels. Each tape reel is individually tensioned by a paddle 157 biasedby a spring 158 into contact with the outer face of the prewound tapereel 184 radially away from the reeler assembly 110. The spring 158 issecured between the paddle 157 and an adjustment rod 159, which may berotated to vary the tension supplied by the spring 158. As in the firstembodiment, it has been found that adjustment of the tensioning devicefor the tape 186 is not normally necessary.

The axes of rotation and 255 of the tape reels i '186 are parallel withthe axis .124 of the reeler assembly The lead attachment assembly 160includes a spot welder 161 having an open jaw' 163 for receivingconductive ribbon 181 wound on the reels-180. The welder 161 isslidably'mounted on its carriage 260 by sleeves 165 on a supportstructure 167; When the dereeler assemblies 130 and 230 are moved totheir second positions, the lead attachment assembly 160 is movable froma rearward position behind the second dereeler assembly 230 to a forwardposition in which its jaw 163 encompasses'ribbons- 181 from bothdereeler assemblies, regardless of the widths of the ribbon on thedereeler assemblies. For this purpose, the lower portion of the weldersupport 167 is cut back to the forward margins of the sleeves 165, toclear the rearward shaft 142 of the dereeler carriage assembly 140.

Merely by way of illustration, theribbon 181 on the reels 180 may be thesame as that on the reel 80 of the first illustrative embodiment, thatis, bare aluminum 1 1/16 inch wide and 0.008 inch thick. The tape 186may then be the same as the tape 86 of the first illustrativeembodiment, that is, woven fiberglass 1% inch wide and 0.004 inch thick.The ribbon reel 180 may have an initial diameter of eighteen inchesandthe tape reel 184 may have an initial diameter of 5 inches.

Also by way of example, the axes of rotation 138 and 238 of the dereelerassemblies 130 and 230 may be separated by a linear distance of aboutfourteen inches from the reeler assembly axis 124 when the dereelerassembly is in its first position and separated a distance of aboutforty inches when in its second position. The axes of rotation 155 and255 of the tape dereeler assembly 150 may be spaced 12% inches and 15inches respectively from the axis of rotation 124 of the reeler assembly110.

The shoe arm 232 of the dereeler assemblies 130 and 230 may be ll incheslong from its pivot point and the rod 233 on which it is pivoted may be6% inches forward of a vertical plane through the axis of rotation 138or 238 of the dereeler assembly and about 10 inches from the axis ofrotation of the dereeler assembly.

The paddle 157 may be 5 k inches long from its pivot, which may bespaced 5% inches from the axis of rotation 155 of the tape dereelerassembly 150.

The operation of this embodiment of machine, which is illustrative offurther aspects ofthe method of this invention, is as follows.

The dereeler assemblies 130 and 230 are moved to the positions shown inFIG. 5, and'their retainer caps 139a removed. Prewound reels of foilribbon 180 are positioned with their side faces against the inward facesof the spools 139 and the retainer caps 139a are replaced and tightened.The rearward dereeler assembly 230 is then moved to its spaced positionand the reel supports 134 are pneumatically released by activating thelatch releases 239 from the control panel 145. The support 134 of thesecond dereeler assembly 230 is moved to its outward position and thesupport 134 of the forward dereeler assembly 130 is moved to its inwardposition. The welder 161 is moved forward and start leads are welded tothe free ends of the ribbons 181. The welder assembly 160 is then movedrearward and the dereeler assemblies 130 and 230 are pneumatically movedto their position radially adjacent the reeler assembly 1 10. A corestructure is then placed in the jaws 113 and 119 of the reeler assembly110. The core structure in this case is a stack 190 of .iron L-laminations 191 for use in a small welder transformer. The laminations191 are merely stacked and not bonded together. The foot of the L" isplaced in the rearward chuck 118 and the upper (forward) face of thefoot is axially aligned with the forward face of the rearward windingplate 121. The forward chuck 112 is moved forward or rearward to matesuitably with the stack 190. Insulative corner spacers 193 are placedalong the long edges of the stack 190 and temporarily held by a strip ofpressure-sensitive tape. A pair of coils are then wound by the methodhereinafter described. The dereeler assemblies and 230 are then moved totheir second, spaced, position pneumatically. It will be seen that theshoes 231 prevent the reels 180 from unwinding and holdthe free ends ofthe ribbons 181 at a convenient height when the dereeler assemblies arein their second position. The welder 161 is moved to its forwardposition and finish leads are welded tothe two ribbons 181.

The remainder of the winding of the first pair of coils is completedby'hand and the coils taped around their outer faces. V I

The latch releases 239 are again activated from the control panel andthe dereeler support assemblies 134 are moved to the positions shown inFIG. 5. Start leads are welded to the free ends of the ribbons and thewelder 161 returned to its rearward position. The dereeler assemblies130 and 230 are then moved to their winding positions. The tape reels184 are shifted on their support shafts 151 by removing the spacers 153and shifting them to the other sides of the tape reels 184, to thepositions shown in FIG. 5. The free end of the insulative tape 186 fromeach tape reel 184 is then brought under the stack 190 and taped to theend of the ribbon 181, extending about one-half inch beyond the end ofthe ribbon 181, with a polyester pressure-sensitive tape. The ribbon andinsulative tape are positioned on the stack 190 with their endsoverlying a spacer 193, and the pressure-sensitive tape is secured tothe next successive spacer 193. The start lead 196 of each ribbon 181 isplaced through the lead slot in the adjacent winding plate,-to keep itout of the way during the winding of a coil 198.

It will be seen that the leads of the first coil wound from the rearwarddereeler assembly 230 may remain in the lead slot of the rearwardwinding plate, but that the leads of the first coil wound from theforward dereeler assembly 130 must be carefully extended to be axiallyaligned with the coil, in order to avoid catching them in the second setof coils to be wound.

The motor 126 is then energized and the second pair of coils 198 arewound. When the counter 129 senses that the required number of turnshave been wound it disconnects the clutch of the clutch-brake 125 andapplies its brake. The dereeler assemblies 130 and 230 are then moved totheir spaced position and the welder 161 moved forward to attach finishleads to the ribbons 181. The ribbons are then cut and the coilscompleted by turning the stack 190 by hand. The tapes 186 are then cut,leaving an overlap beyond the ends of the ribbons 181. The finishedcoils are then wrapped with a turn of polyester pressure-sensitive tape.The coils are complete at this point. The core 190 may then be removed.It will be seen that the coils 198 serve to hold the laminationscompressed after the core 190 is removed from the chucks 112 and 119.

The appropriate start and finish leads of the coils are then welded toeach other in any conventional manner for joining foil conductors. Theremaining leads of the coils are left free for later securement toconductors when the transformer is fully assembled.

If it is desired to wrap additional coils over the coils 1 98, thewrapped stack 1 90 may be set aside until the prewound coils 180 areusedup and reels of ribbon and tape of the proper size for theadditional coils are placed on the dereeler assemblies 120 and 230 andon the tape dereeler assembly 150. Alternatively, a second machine forwrapping these coils may be'provided.

When all of the coils required for a transformer have been wound on thetwo L-shaped laminated cores used in the transformer, the two sectionsmay be held to- 'gether by conventional means, such as stiffener platesextending across the junction between the two halves and held to thelaminations by through-bolts. The entire transformer may then be dippedin varnish and the varnish baked, as is 'well known in the art. Thestiffener plates, with theirthrough-bolts, and the varnish hold thelaminations making up the foot of the L to each other.

- Illustratively, the length of ribbon between the shoe 231 and the takeup point on the coil 198 being formed may be on the order of one tothree inches when the prewound re'el 180 is initially placed on thedereeler assembly, and on the order of nine to eleven inches when theprewound reel is depleted. It will be seen that in this embodiment, thesweep of the foot 192 of the core 190 limits the allowed movement of thedereeler assembly 230 toward the reeler assembly 110. It has been foundthat towards the end of the reel the remarkably true trackingprovided'by this machine and method become somewhat less satisfactory,although still within permissiblemanufacturing tolerances. It thereforemay be advisable to remove the reels 180 from the dereeler assembliesbefore they are completely exhausted, and to use the diminished reelsfor other purposes or in machines, such as that shown in FIGS. l-3,which are relatively unaffected by the reel diameter. The lengths of thetape between the tape dereeler and the coil are on the order of 13inches and 15 inches respectively and are relatively unchanged as thecoils are wound and as the prewound tape reels decrease in diameter.

" It will also be seen that the angle between the ribbon 181 and tape186 being taken onto the core 190 is at least 90 degrees, so that thetensioning of the foil and the tape are essentially independent of eachother, as in'the first embodim'ent. 7

As in the first embodiment, it has been found that,

although the magnetic clutch 137 must be adjusted as the diameter of theprewound ribbon reel decreases, it is unnecessary to provide anautomatic feed back system to obtain satisfactory results.

The particular dereeler and tape dereeler assemblies of this embodimentare not particularly adapted to reversing the direction of winding ofthe core 190 by reversing the direction of rotation of the reelerassembly 110. However, the core 190 may be reversed in the reelerassembly to achieve this result.

A third embodiment of foil coil winding machine is shown in FIG. 6. Thisembodiment differs from the prior embodiment in that it provides atakeoff point from the prewound ribbon reel 180 which is fixed withrespect to the reeler assembly 110, as in the first illustrativeembodiment, yet provides a shoe for preventing the reel 180 fromunwinding when its dereeler assembly is moved to its second position,spacedfrom the reeler assembly 110.

A roller 391 supported by an arm 392 secured to the base 170 bearsagainst the outer face. of the reel 180 when the dereeler assembly 330is moved to a first position adjacent the dereeler assembly 1 10. Eachmodified dereeler assembly 330. has a modified shoe arm 332 supporting ashoe 331. The shoe arm 332 extends below its pivot point and isprovided, at its lower end, with a wheel 333 which is engaged by a cam334 on the base 170. The cam 334 moves the shoe 331 away from the reel180 and below the roller 391 when the dereeler assembly 330 is moved toits first position. When the dereeler assembly 330 is moved toward itssecond position, the' shoe arm 332 is released by the cam 334 and isbiased into engagement with the outer face of the reel 180 by a spring335.

It will be seen that if the core being wound has no radially extendingleg, or one of moderate length, as shown in. broken lines in FIG. 6,this arrangement allows the takeoff point of the ribbon 181 from thereel 180 to remain the same relative to the reeler assembly 110. Thelength of ribbon between the reel 180 and a coil being formed isconsiderably less than the initial diameter of the prewound reel 180. I

Numerous variations in the machine and method of this invention, withinthe scope of the appended claims, will occur to those skilled in the artin the light of the foregoing disclosure. 1 I

I claim:

1 A machine for simultaneously winding a pair of electrical coilsdirectly onto a rectangular magnetically permeable core, each of saidelectrical coils including a thin ribbon of electrically conductivematerial convolutely wound in an axially aligned coil, said coils beingspaced axially from each other, said machine including a driven reelerassembly having a rotating part for winding the coils; a first dereelerassembly for rotatably supporting a prewound'reel of electricallyconductive ribbon in a first plane normal to the axis of rotation ofsaid rotating part; a second dereeler assembly for rotatably supportinganother prewound reel of electrically conductive ribbon in a secondplane parallel to said first .plane and spaced from said first plane;and carriage means for independently supporting said dereeler assembliesfor movement of each of said dereeler assemblies in its respective saidplane from a first position adjacent said reeler assembly for windingsaid coil to a second position spaced from said reeler assembly.

2. In a machine for winding a rectangular electrical coil including athin ribbon of electrically conductive material convolutely wound in anaxially aligned coil, including a driven reeler assembly for winding thecoil and a foil dereeler assembly for rotatably supporting a prewoundreel of electrically conductive ribbon, the improvement comprising afollower engaging a radially outer face of said prewound reel ofconductive ribbon, said follower defining a takeoff point of saidconductive ribbon from said reel, said follower being spaced from saidreeler assembly and comprising the sole means engaging said conductiveribbon between said prewound reel and'said coil during winding of saidcoil, thereby defining a length of an unsupported reach of ribbonbetween said reeler assembly and said follower; means for biasing saidprewound reel and said follower into engagement, whereby said followercontinues to contact said outer face of said reel as said ribbon is'dereeled from said prewound reel; and means for'mounting said followerina fixed position with respect to said reeler assembly, whereby saidtakeoff point remains fixed with respect to said reeler assembly as saidribbon is dereeled from said prewound reel.

3. In a machine for winding an electrical coil including a thin ribbonof electrically conductive material convolutely wound in an axiallyaligned coil, including a driven reeler assembly, having a rotating partfor winding the coil, and a foil dereeler assembly for rotatablysupporting a prewound reel of electrically conductive ribbon, theimprovement comprising carriage assembly means for slidably supportingsaid foil dereeler assembly for sliding movement from a first positionadjacent said reeler assembly, for winding said coil, to a secondposition, lying in a common plane normal to the axis of rotation of saidrotating part with said first position, spaced from said reelerassembly, said dereeler assembly including means for shiftablysupporting said dereeler assembly on said carriage assembly means, forshifting said dereeler assembly axially on said carriage assembly meansto wind a second coil axially spaced from said first coil.

4. In a machine for winding a rectangular electrical coil including athin ribbon of electrically conductive material convolutely wound in anaxially aligned coil, including a driven reeler assembly, having arotating part for winding the coil, and a foil dereeler assembly forrotatably supporting a prewound reel of electrically conductive ribbon,the improvement comprising carriage means for movably supporting saidfoil dereeler assembly for movement from a first positon adjacent saidreeler assembly, for winding said coil, to a second position, lying in acommon plane normal to the axis of rotation of said rotating part withsaid first position, spaced from said reeler assembly; follower meansfor engaging a radially outer face of said prewound reel of conductiveribbon at least when said reel is in said first position, said followermeans defining a takeoff point of said conductive ribbon from said reel,said follower means being spaced from said reeler assembly andcomprising the sole means engaging said conductive ribbon betweeen saidprewound reel and said coil during winding of said coil, therebydefining a length of an unsupported reach of ribbon between said reelerassembly and said follower means; means biasing said prewound reel andsaid follower means into engagement, whereby said follower meanscontinues to contact said outer face of said reel as said ribbon isdereeled from said prewound reel; lead connecting means for attaching anelectrical lead to a reach of ribbon between said reeler assembly andsaid dereeler assembly when said dereeler assembly is in said secondposition, and means rendering said lead connecting means axially movableinto said plane normal to said axis of rotation of said rotating partwhen said dereeler assembly is in said second position and out of saidplane when said dereeler assembly is in said first position.

5. In a machine for winding a rectangular electrical coil including athin ribbon of electrically conductive material convolutely wound in anaxially aligned coil, including a driven reeler assembly, having arotating part for winding the coil, and a foil dereeler assembly forrotatably supporting a prewound reel of electrically conductive ribbon,the improvement comprising carriage means for movably supporting saidfoil dereeler assembly for movement from a first position adjacent saidreeler assembly, for winding said coil, to a second position, lying in acommon plane normal to the axis of rotation of said rotating part withsaid first position, spaced from said reeler assembly; follower meansfor engaging a radially outer face of said prewound reel of conductiveribbon at least when said reel is in said first position, said followermeans defining a takeoff point of said conductive ribbon from said reel,said follower means being spaced from said reeler assembly andcomprising the sole means engaging said conductive ribbon between saidprewound reel and said coil during winding of said coil, therebydefining a length of an unsupported reach of ribbon between said reelerassembly and said follower means; means biasing said prewound reel andsaid follower means into engagement, whereby said follower meanscontinues to contact said outer face of said reel as said ribbon isdereeled from said prewound reel, and electrically variable means insaid coil dereeler assembly for impeding the rotation of said prewoundreel, said impeding means and said follower comprising the soletensioning means for said conductive ribbon.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION 3,179, 47;December 18, 1973 Patent No. Dated It is certified that error appears inthe above-identified patent and that said Letters Patent are herebycorrected as shown below:

Abstract Add the following:

when a coil is wound except for about a turn and a half, the dereelerassembly is moved to its second positmon, a lead is secured to the foil,the foil is cut and winding of the coil is completed. A second coil orpair of coils may bewound on the same piece by shifting the dereelerassembly axially of the coils previously formed.

Specification Col. 5-, line 1, "shapd" should be "shaped"; I Col. 5,line. '56, "attachement" should be "attachment"; Col. 8, line &5, "11"should be "111" Col. 13, line 5, "120" should be "130";

I Signed and scaled this 6th day of August 1974.

(SEAL) Attestz' MCCOY lylf GIBSON, JR. c. MARSHALLYDANN AttestlngOfficer Commissioner of Patents

1. A machine for simultaneously winding a pair of electrical coilsdirectly onto a rectangular magnetically permeable core, each of saidelectrical coils including a thin ribbon of electrically conductivematerial convolutely wound in an axially aligned coil, said coils beingspaced axially from each other, said machine including a driven reelerassembly having a rotating part for winding the coils; a first dereelerassembly for rotatably supporting a prewound reel of electricallyconductive ribbon in a first plane normal to the axis of rotation ofsaid rotating part; a second dereeler assembly for rotatably supportinganother prewound reel of electrically conductive ribbon in a secondplane parallel to said first plane and spaced from said first plane; andcarriage means for independently supporting said dereeler assemblies formovement of each of said dereeler assemblies in its respective saidplane from a first position adjacent said reeler assembly for windingsaid coil to a second position spaced from said reeler assembly.
 2. In amachine for winding a rectangular electrical coil including a thinribbon of electrically conductive material convolutely wound in anaxially aligned coil, including a driven reeler assembly for winding thecoil and a foil dereeler assembly for rotatably supporting a prewoundreel of electrically conductive ribbon, the improvement comprising afollower engaging a radially outer face of said prewound reel ofconductive ribbon, said follower defining a takeoff point of saidconductive ribbon from said reel, said follower being spaced from saidreeler assembly and comprising the sole means engaging said conductiveribbon between said prewound reel and said coil during winding of saidcoil, thereby defining a length of an unsupported reach of ribbonbetween said reeler assembly and said follower; means for biasing saidprewound reel and said follower into engagement, whereby said followercontinues to contact said outer face of said reel as said ribbon isdereeled from said prewound reel; and means for mounting said followerin a fixed position with respect to said reeler assembly, whereby saidtakeoff point remains fixed with respect to said reeler assembly as saidribbon is dereeled from said prewound reel.
 3. In a machine for windingan electrical coil including a thin ribbon of electrically conductivematerial convolutely wound in an axially aligned coil, including adriven reeler assembly, having a rotating part for winding the coil, anda foil dereeler assembly for rotatably supporting a prewound reel ofelectrically conductive ribbon, the improvement comprising carriageassembly means for slidably supporting said foil dereeler assembly forsliding movement from a first position adjacent said reeler assembly,for winding said coil, to a second position, lying in a common planenormal to the axis of rotation of said rotating part with said firstposition, spaced from said reeler assembly, said dereeler assemblyincluding means for shiftably supporting said dereeler assembly on saidcarriage assembly means, for shifting said dereeler assembly axially onsaid carriage assembly means to wind a second coil axially spaced fromsaid first coil.
 4. In a machine for winding a rectangular electricalcoil including a thin ribbon of electrically conductive materialconvolutely wound in an axially aligned coil, including a driven reelerassembly, having a rotating part for winding the coil, and a foildereeler assembly for rotatably supporting a prewound reel ofelectrically conductive ribbon, the improvement comprising carriagemeans for movably supporting said foil dereeler assembly for movementfrom a first positon adjacent said reeler assembly, for winding saidcoil, to a second position, lying in a common plane normal to the axisof rotation of said rotating part with said first position, spaced fromsaid reeler assembly; follower means for engaging a radially outer faceof said prewound reel of conductive ribbon at least when said reel is insaid first position, said follower means defining a takeoff point ofsaid conductive ribbon from said reel, said follower means being spacedfrom said reeler assembly and comprising the sole means engaging saidconductive ribbon betweeen said prewound reel and said coil duringwinding of said coil, thereby defining a length of an unsupported reachof ribbon between said reeler assembly and said follower means; meansbiasing said prewound reel and said follower means into engagement,whereby said follower means continues to contact said outer face of saidreel as said ribbon is dereeled from said prewound reel; lead connectingmeans for attaching an electrical lead to a reach of ribbon between saidreeler assembly and said dereeler assembly when said dereeler assemblyis in said second position, and means rendering said lead connectingmeans axially movable into said plane normal to said axis of rotation ofsaid rotating part when said dereeler assembly is in said secondposition and out of said plane when said dereeler assembly is in saidfirst position.
 5. In a machine for winding a rectangular electricalcoil including a thin ribbon of electrically conductive materialconvolutely wound in an axially aligned coil, including a driven reelerassembly, having a rotating part for winding the coil, and a foildereeler assembly for rotatably supporting a prewound reel ofelectrically conductive ribbon, the improvement comprising carriagemeans for movably supporting said foil dereeler assembly for movementfrom a first position adjacent said reeler assembly, for winding saidcoil, to a second position, lying in a common plane normal to the axisof rotation of said rotating part with said first position, spaced fromsaid reeler assembly; follower means for engaging a radially outer faceof said prewound reel of conductive ribbon at least when said reel is insaid first position, said follower means defining a takeoff point ofsaid conductive ribbon from said reel, said follower means being spacedfrom said reeler assembly and comprising the sole means engaging saidconductive ribbon between said prewound reel and said coil duringwinding of said coil, thereby defining a length of an unsupported reachof ribbon between said reeler assembly and said follower means; meansbiasing said prewound reel and said follower means into engagement,whereby said follower means continues to contact said outer face of saidreel as said ribbon is dereeled from said prewound reel, andelectrically variable means in said coil dereeler assembly for impedingthe rotation of said prewound reel, said impeding means and saidfollower comprising the sole tensioning means for said conductiveribbon.